The latest poll is the first one showing Brown with less than a double-digit lead. The survey has a 3 percentage point margin of error.

Brown leads among independent voters 42 percent to 38 percent. He also leads 50 percent to 34 percent among women, while Mandel leads 46 percent to 41 percent among men.

A total of 41 percent of voters view Brown favorably and 30 percent unfavorably. For Mandel the numbers are 30 percent favorable and 18 percent unfavorable. A hefty 51 percent don't know enough about Mandel to have an opinion.

“Is Sen. Sherrod Brown hearing the footsteps of State Treasurer Josh Mandel?” Peter Brown, assistant director of Quinnipiac’s polling institute, said in a statement. “Ohio voters say 44 to 38 percent that Brown deserves another six years in the Senate . . . short of the 50 percent any incumbent would like to have.”